H W Brands in The Guardian:
Barbara Walter does not expect to see a civil war in the US of the order of the conflict that tore the nation apart in the 1860s, but that’s chiefly because civil wars are fought differently these days. And it’s about the only comfort a concerned reader can take from this sobering account of how civil wars start and are conducted in our time. Walter is a professor of international relations at the University of California, San Diego, and a consultant to various government and international agencies. She has studied civil wars and insurgencies for three decades, and iIn this book she draws on her own work and that of other researchers to produce a typology of the descent into organised domestic violence.
The key concept is that of “anocracy”, a transition stage of government between autocracy and democracy. The transition can be made in either direction, and it is during the transition that most civil wars erupt. Autocracies possess sufficient powers of repression to keep potential insurgents in check; democracies allow dissidents means to effect change without resorting to violence. But when autocracies weaken, repression can fail, and when democracies ossify, the release valves get stuck.